Have to, must and should for obligation and advice

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Have to, must and should for obligation and advice

Oliver and Alfie visit the local pet shop, where they are surprised to see Amy. Meanwhile, something is on Sophie's mind ...

Instructions

As you watch the video, look at the examples of have to, must and should. They are in red in the subtitles. Then read the conversation below to learn more. Finally, do the grammar exercises to check you understand, and can use, have to, must and should correctly.

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We use have to / must / should+ infinitive to talk about obligation, things that are necessary to do, or to give advice about things that are a good idea to do.

Must and have to are both used for obligation and are often quite similar. They are both followed by the infinitive.

I must go now. / I have to go now.

Are these exactly the same?

Well, almost. We often use must for more personal opinions about what it is necessary to do, and have to for what somebody in authority has said it is necessary to do.

I must remember to get a present for Daisy. (my opinion) You have to look after their hair regularly. (dog experts say so)Do you have to wear a tie for school? (asking about school rules)

Which verb do people use more?

Have to is more frequent in conversation; must is used more in formal writing, for example in written notices.

Passengers must fasten their seat-belts.

Do they change in form for I, you, he, she, etc.?

Have changes in the third person singular (he/she/it has); but must doesn’t change. It’s a modal verb and modals don’t change.

I think I’ve heard have got to. Is that correct?

Yes, we use both have got to, for obligation, and had better, for advice, a lot in speaking.

You've got to be careful with a cat
You'd better get something a bit quieter.
I'd better go – I mustn't miss the helicopter!

So they’re not used in formal writing?

No. There’s something very important about must and have to. The positive forms are very similar in meaning, but the negative forms are completely different.

You mustn’t forget ...
(don’t forget - you have no choice)If you don't like him, you don't have to see him again.
(there is no obligation to see him again, but you have a choice)

Umm, I’m still a bit confused ...

Here's an example you can remember:In a non-smoking area you mustn’t smoke, but in a smoking area you don’t have to smoke but you can if you want to.

Ah! Right, I mustn’t forget that.

No, you mustn’t! OK, let’s look at advice, telling people what you think is a good idea. We use should for advice, or making suggestions, and must for strong advice.

You must go for a walk with the dog at least once a day.
Maybe you should go for a coffee or lunch and see how you feel?
You shouldn't leave it on the street.

I think I’ve heard people use should in other ways, like 'he should be here in a minute' – that’s not advice, is it?

No, that’s talking about what is likely or probable. We’ll look at that use another day. We use modal verbs in different ways.

Transcript

Transcript:

Oliver: Amy! Hi! What are you doing here?Amy: It's my new Saturday job. Hi, Alfie.Oliver: Really?Alfie: Hi.Amy: Yes. I want to study veterinary science at university and my parents suggested I should get some experience of working with animals.Oliver: And do you like it?Amy: It's my first day ... Anyway. What can I do for you?Oliver: Well, I've got some money and I've decided I'd quite like a pet. Daisy and Mum like the idea, but Mum says I mustn't get a spider, a scorpion or a snake.Amy: That's understandable. Alfie: Let's see the dogs. Oh yeah! Look at these, mate! Puppies! What's that white one?Amy: That's a Dalmatian.Alfie: But they've got black spots, haven't they?Amy: Not when they're puppies, no. You have to wait until they're bigger. Then the spots appear.Alfie: Ah, I never knew that. Dalmatians are quite big, aren't they?Amy: Yes, they are. You should really have a garden.Oliver: Well, we've got one ...Amy: And you have to take them out for a walk twice a day. Well, you don't have to go twice, but you must go at least once. Every day. Rain, snow, sun ... every day. And you mustn't forget to take two or three small plastic bags when you go out.Oliver: Plastic bags?Amy: Well, when your dog … you shouldn't leave it on the street. You should always clean it up and put it in the bin.Oliver: Hmm. And a smaller dog? Should I get one of these?Amy: They're Yorkshire terriers. They're very small ...Alfie: ... and noisy! You'd better get something a bit quieter, Ollie. Think of your neighbours!Oliver: How about that one?Amy: As an adult, Old English Sheepdogs are extremely large – like that one. And you've got to look after their hair regularly. You should brush them as often as possible, and get their hair cut.Oliver: Hmm. What about a cat?Alfie: We used to have a cat. She was a bit unfriendly. She used to scratch the sofa – and our legs – and she stole food if you left it for a moment. You've got to be careful with a cat – some are nice, but some are ... well ...Oliver: Oh, ff. A turtle? They're small and quiet and they don't have hair ...Amy: They grow. And then you have to buy a bigger tank. You'd better buy a thermostat and a filter if you want a turtle. And you mustn't forget to change the water; they don't smell great ...Oliver: What about a hamster?...

Sophie: I don't know what I should do. I mean, I don't want you to feel uncomfortable ...Daisy: I don't mind! And if you like him ... why not? He has to decide if he wants to go out with the mother of a student, though. But he seems nice. Maybe you should go for a coffee or lunch and see how you feel? If you don't like him, you don't have to see him again.Sophie: I shouldn't be asking you about this sort of thing! Oh, but I feel like a teenager. Why do these things have to be so complicated?Daisy: It's not complicated, Mum! You mustn't forget, he's the one who suggested going for a drink, so he obviously likes you – and you obviously like him! What's complicated?Sophie: I'm in New Zealand! I'm about to go and fly over volcanoes ... it's not easy to combine my kind of life with ... well, with a romance!!Daisy: You'll be home next week, and maybe you should take some time off travelling. Spend some time with us. And with him. And I'll be leaving school in a year ... so ... go on, Mum. Life's too short! You should phone him!Sophie: Well, I'll think about it. I'd better go – I mustn't miss the helicopter! Is Oliver there?Daisy: No, he's out buying that pet ... ah no, here he is. Ollie, it's Mum.Oliver: Hi, Mum!Sophie: Did you get anything?Oliver: Yes I did! And his name's Hannibal.

Discussion

Comments

I've got a parrot and dog in my house .Parrot is so cute and cleaver.She is so impatient because she don't get angry all of time .One good thing have a parrot is control of pet .Parrot is eazy to control under the human , but I must feed everyday to the parrot .
dog is most relevant animals all of creature I think. My dog occasionally bark to other people,but my dog is impatient. He is walking around in my house.

Hi ph16c033! It's grammatically possible to say that but it depends what you mean. What do you want to say? If you're just saying it's an obligation to go to Mumbai, it's not necessary (and it's actually incorrect) to use 'must' and 'have to' at the same time. Best wishes, Joanna (LearnEnglish Teens team)

When I was a child, I watched the film:"Kommisar Rex". I always dream that one day I have one dog like this. Eventually, my dream has come true. I have a German Shepherd Dog. He is very big and smart. If any thieves intend to break into my house, it will be the biggest mistake in their life. The disadvantage is that I have to clean him every week and spray insecticide every month for prevention of fleas and ticks.

Hi learn English team ,
hop you all doing well.
I have a question please it about the above practice.
Why I have to say 1-"Why do we always have to come to the same cafe?
And I mustn't say 2- "Why we always have to come to the cafe?
What is the different between two sentence?

It’s a question, and most questions need to have an auxiliary verb (unless they are with a modal verb like “can” or “should”).
In this example, the verb is “have to”, which needs some form of “do” as the auxiliary verb (“do” or “does” in the present simple, “did” in the past simple). So --> “do we have to”.
Jonathan (LearnEnglish Teens Team)

I had a Sirio Hamster, its name was Natasha Romanov, she was very cute, nice and above all a good companion and great friend. I had to clean each week the substrate of her cage. I think that a hamster as pet is a good idea, however, you should buy toys and have to play with it.
Moreover, you must provide a correct diet, this must not contain high fats levels and acid fruits as a lemon.
Now, I am considering If I should buy a Chinchilla, I love this kind of pet, however, I should not buy it because my mom dislikes animals.

No, I do not have a pet, but I want to buy a cat.Its advantages that it will give me love and it will be my friend and play with me .Its disadvantage that my sister my be afraid from it because she is so little to adapt with a cat in the home .

I haven't got any pets, but I would like to have a dog. A disadvantage is that you must go for a walk with the dog at least once a day, but when you love your dog you will see that there are also many advantages. You can learn a lot from it and it will give you a lot of satisfaction.

I don't have a pet.I like cats and hamsters.
The advantage of having that particular animal are:learning a lot of things about animals like how do they live and learning about the animal world ,but the disadvantage is that you must be responsable completely for his life.